Zarathustra's Roundelay is a poem that figures as a central motif in the book Thus Spoke Zarathustra by Friedrich Nietzsche. The roundelay first appears in "Chapter 59: The Second Dance-Song", as a psychological revelation that precedes "Chapter 60: The Seven Seals", a conclusion and affirmation of Zarathustra's middle-aged philosophical ventures. Then, in the second last chapter, "The Drunken Song", Zarathustra elaborates upon and explains his roundelay, revealing its connection to the Eternal Recurrence.

The roundelay was used as the text for the 4th movement (originally titled "What Man Tells Me") of Gustav Mahler's 1895 3rd Symphony. It was also used as the text of the fourth and final movement of Lukas Foss' 1960 Time Cycle.